Process of purifying brine.



.UNTTED STATES PATENT @IFFICE GERHARD NICOLAAS VIS, OF SOHWEIZERHALLE, SWITZERLAND.

PROCESS OF PURlFYlNG BRINE.

SPECIFICATION forming part of Letters Patent No. 658,303,'dated September 18, 1900. Application filed May 3, 1899- Serial N 0. 715,480. (No specimens.)

To all whom it may concern: sum would require 4.57 3 kilograms of sodium Be it know that I, GERHARD NIOOLAAS VIs, carbonate, (Na,OO doctor of philosophy and chemist, a subject Cao contained of the ueen of the Netherlands residin at in one hulrG'rsmn cnNa soda) Q g bodmm sulfate drecl cubic lmined in one rqui reii for Schweizerhalle, near Basel,Switzerland,have added to one centimeters bic meter precipitating 55 i t d a new d f l Process f h gf fi i ofthetreated of the brine thisremainder Purification of Brine; and I do hereby de- Elfhf treated of gypsum. clare that t he following is a full, clear, and Kilograms Grams Kflogmms exact descrlption of the invention, which will 5. 2 1o enable others skilled in the art to which it it; 8353?; 2:33? $3326 60 appertains to make and use the same. 4 1-693 1-329 The present; invention relates to the purifi- Gypsum removed from one cubic meter of brine by the addit'f1lft'thfi'tl cationof brine; anditconsists ofan improved {1on0 SI aeqsm e is 00 process for removing the calcium sulfate or gar,- 15 gypsum contained in the brine in dissolved 65 state. 41175 In a prior application, Serial N 0. 700,098, filed December 23, 1898, I have described a The separation of the gypsum is accelerated process for purifying brine by means of an if the brine, after the addition of the sufate,

2o addition of a solution of calcium chloride, is kept constantly stirred for twenty-four 76 whereby the sulphates of sodium, potassium, hours, about, or once boiled up or heated to and magnesium present in the brine are transa lower degree for a longer period, which may formed into calcium sulfate, which precipibe shortened by stirring. After the separatates, and a large percentage of the calcium tion of the brine from the precipitated gypsulphate originally present in the brine is sum the remainder of dissolved gypsum is re- 7 caused to separate out. This process is esmoved from the former in the usual manner pecially advantageous for places where soluby the usual means for this purpose, prefertions of calcium chloride are to be had ata low ably by means of sodium carbonate. cost-as, for instance, in the neighborhood of The quantity of sulfate to be applied'in the soda-Works. In other places this process may first phase of the process must be calculated 80 be as costly as the old method of removing according to the amount of gypsum known the gypsum by means of soda (carbonate of or determined by analysis to be contained in sodium) or other known precipitates. I have the brine.

found that a similar effect as that produced The gypsum separated from the brine is of by the addition of calcium chloride will be a very fine quality, and by its industrial use 85 brought about by dissolving in the brine a the cost of the soda or other precipitant may convenient quantity of easily-soluble sulbe largely reduced. fates. This procedure has also the effect of In carrying the process into effect the causing a large percentage of the gypsum to Schweizerhalle brine, for instance, is treated separate out, so that a comparatively-small as follows: To every cubic meter of this brine 9o quantity of soda or other precipitant will sufare added about fifteen kilograms of sofice to complete the removal of gypsum. Of dium sulfate. When the latter is completely said sulfates I prefer to use sodium sulfate dissolved, the compound solution may once or Glauber salt. The purifying effect of be boiled llpl;. 6., heated to aboutl07 centisaid addition of sodium of sulfate may be grade, if fuel is cheap. In general we prefer 5 seen from the following table, taking the to keep said compound solution constantly brine of Schweizerhalle, near Basel, as an exstirred for about twenty-four hours. An ample. Normally this brine contains 5.868 abundant precipitation of gypsum takes kilograms of gypsum (GaSO,,) per cubic meplace. The precipitate is then allowed to ter to be precipitated. This quantity of gypsettle and the brine drawn 015?. The latter 10o now contains only 2.276 grams of calcium sulfate per liter. Thisremainder of gypsum is then precipitated in the usual manner by treating the brine with one or more of the well-known means for converting gypsum into calcium carbonate. I prefer to use so- 'dium carbonate, as in reacting with the gypsum it is transformed into sulfate of sodium. The sodium carbonate is added in the quantity needed for the conversion of the entire remainder of gypsum, which is to be determined by chemical test in the ordinary manner, and the mixture stirred or heated and stirred for awhile, when the calcium carbonate formed is allowed to settle, and finally the brine is separated from the precipitate.

To obtain the chloride of sodium (common salt) contained in the purified brine free from gypsum, the brine is evaporated in the usual manner. The mother-liquor remaining after the removal of the salt crystals contains the sodium sulfate originally added, as well as that formed by the addition of soda, and is utilized in a subsequent process,

What I claim as my invention, and desire to secure by Letters Patent of the United States, is-

1. The process of purifying brine from gypsum which consists in dissolving in the brine to be treated a quantity of an easily-soluble sulfate exceeding the percentage of gypsum present, maintaining the liquor for some time in a state of motion, removing the gypsum separated out, treating the liquor with a reagent capable of transforming the remainder of dissolved gypsum into an indissoluble calcium compound, and separating the liquor from the precipitate, substantially as and for the purposes specified.

2. The process of purifying brine from gyp sum which consists in dissolving in the brine to be treated a quantity of sodium sulfate exceeding the percentage of gypsum present, stirring the liquor, removing the gypsum separated out, treating the liquor with sodium carbonate, and separating it from the pr'ecipitate, substantially as and for the purposes specified.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

GERl-IARD NICOLAAS VIS,

Witnesses i GEORGE GIFFORD, ALBERT GRAETER. 

